Low-water alarm



(No Model.) W. D. MoLAUOHLIN 8a A. PHILLIPS.

LOW WATER ALARM.

No. 505,720. Patented Sept. 26, 1893.

U ITED STATES PATENT OFFICE.

WILLIAM D. MCLAUCHLIN AND AUSTIN PHILLIPS, OF OORUNNA, MICHIGAN.

LOW-WATER ALARM.

PEGIFlGATION forming part of Letters Patent No. 505,720, dated September 26, 1893.

Application filed November 14,1891 Serial No. 411,864 (No model.)

T0 at whom it may concern.-

Beitknownthat we, WILLIAM D.MCLAUGH LIN and AUSTIN PHILLIPS, citizens of the United States, residing at Oorunna, in the county of Shiawassee and State of Michigan, have invented certain new and useful Improvements in Lowater Alarms; and we do declare the following to be a full, clear, and

exact description of the invention, such as operated by a float-actuated lever; and con:

sists in a specific construction of valve and operative mechanism, incident to the location and special employment'of the parts, as hereinafter fully set forth, the essential features of which being pointed out particularly in the claims.

The object of this invention is to provide a valve that may be located within the steam space of theiboiler, in which the employment of the stuffing-box around the valve-stem, is obviated, giving said stem free play, and a further provision, whereby, by means of a float-actuated lever engaging said valve-stem, the valve may be opened to sound the alarm- Whistle when the water in the boiler has fallen to a dangerous point. This object is attained by the mechanism illustrated in the accompanying drawings, in which- Figure 1, is a cross section through a portion of a boiler, showing the valve and its operating float-lever located therein, and the exterior alarm whistle connected with said valve through the shell of the boiler. Fig. 2, is an enlarged vertical section through the valvecase, and the upper end of the float-lever. Fig. 3, is anenlarged perspective of the upper bifurcated end of said lever.

Referring to the letters of reference, A, designates the shell of the boiler, and B, the up per tier of flues.

G, designates a nipplescrewed through the shell of the boiler, its outer end receiving a coupling D, into which is screwed the pipe E, carrying the whistle F. Secured to the lower end of the nipple O, is the valve-case H, the interior of which is divided by the central partition I, forming on one side the chamber J, that communicates with the whistlepipe, and on the other side the chamber K, that communicates with the steam space in the boiler, as shown in Fig. 2. There is a central aperture through the partition I, which is closed by the valve (1. The inner end of the stem 1), of said valve passes through said aperture and lies in a socket G, formed in the outer wall of the chamber J. In the outer wall of the chamber K, an enlargedaperture is formed which admits of the introduction of the valve a, to saidchamber, said aperture being closedby the hollow screw-cap L through which the valve-stem passes (loosely) and which supports the outer end thereof. P, designates a coiled spring that environs the valve-stem 1), between the valve a, and the cap L, and normally holds said valve on its seat. By this construction of valve-case and valve, the packing around the valve-stem is obviated, producing a sensitive Working valve that is easily actuated by .the vibrations of the float-lever, while in the ordinary construction of valve, with stem passing through the outer wall of the chamber J, the stuffing-box cannot be dispensed with, as the steam would enter the chamber J, around the loose valve-stem,

and'said chamber being in communication with the whistle F, said whistle would be continuously blown; andif packingis used around the valve-stem to stop said ingress of steam, the force required to move said valve will be so great that the power exerted by the float lever will be insufficient to actuate it, whereby the ordinary constructed valve, in this practical employment, is rendered impracticable and inoperative, while the valve herein shown, although quite similar in appearance,

overcomes these objections, and is highly effective in operation.

Projecting from the lower end. of the valvecase is a horizontal bracket R, the outer end of which is provided with a slot 0, that receives the flattened portion d," of the lever S, having the aperture 6, and which is pivotally secured in said slot by the thumb screw or bolt, '5, passing through saidparts. The upper end of the lever S, is bifurcated, forming the curved forks h, between which the stem 1) passes, the outer end of said stem being screwthreaded to receive the disk n and set nut 25, that affords an adjustable bearing against which the curved forks h, of the lever S, engage to draw the stem b, and actuate the valve a. By reason of the curved faces of the forks h, bearing against the disk n, the valve stem moves freely horizontally, while said forks, by the action of the lever, travel in the arc of a circle, by which means the binding of the valve-stem in its bearings is obviated.

T, designates a float attached to the free end of the lever S, and which operates said lever by the rise and fall of the water in the boiler.

It will'now be apparent that, in a boiler provided with this improved device, when the. water has fallen so low' as to reach a danger-' ous height above the flues, the float -lever" will draw upon the valve-stem and open the valve permitting the steam to pass upward and blow the whistle, calling attention to the condition of the water in the boiler, the point of water level at which the whistle shall be blown,being determined by adjusting the bearing disk n, on the threaded end of the valve-stem, as will be readily understood. As the water in the boiler is replenished, it raises the float, releasing the valve a, when said valve will close and stop the sounding of the alarm.

We are aware that low water alarms have been made in which there was employed a valve case havingtwo independent chambers that communicate respectively with the whisside a chamber opening in the interior of the 5 boiler, and havinga central aperture communicating with said chambers, the valve to close said aperture, said valve being located in the chamber communicating with the boiler, the valve stem havingits inner end loosely supported in the wall of the valve case, its outer end passing freely through the outer Wall of the chamber communicating with the interior of the boiler, the cap around the end of said valve stem that passes through the wall of said chamber, the spring environing said outer end of the valve stem and interposed between said cap and valve, the float lever engaging the valve stem to operate the valve to draw it from its seat, as set forth.

2. In a low-water alarm, the combination of the whistle, the boiler, the valve-case located in the boiler and communicating with the whistle, the valve in said case, the valve-stem passing freely through the wall of said case and carrying a bearing disk on its outer end, the pivoted-float lever having the curved forks at its upper end and between which the valve-stem passes, the curved faces of said forks adapted to bear against the disk on the valve-stem to actuate the valve, as set forth.

3. In a low water alarm, the combination of the whistle, the boiler, the valve-case located within the boiler and communicating with thee whistle, the valve-stem passing loosely through the wall of said case and carrying the adjustable bearing disk, the bracket ex tending from the valve case, the float-lever pivoted thereto, said lever having the curved forks at its upper end, the valve-stem passing between said forks, the curved faces of which are adapted to bear against the adjustable disk on the end of the valve-stem, substantially as specified.

In testimony whereof we affix our signatures in presence of two witnesses.

WILLIAM D. MOLAUCHLIN. AUSTIN PHILLIPS.

Witnesses:

H. R. WHEELER, E. S. WHEELER. 

